Elastomers For Diaphragms

DiaCom has developed an extensive inventory of elastomers (rubber compound) formulations to meet the demands of a wide range of rolling diaphragm applications and maintains a full-time Rubber Chemist on-staff, constantly working to develop rubber formulations to meet the demands of an ever-changing industry.

DiaCom works with all types of rubber materials, such as Nitrile, EPDM, Neoprene, Fluorosilicone, Silicone, SBR, Fluoroelastomers (Viton®), Hydrin and Vamac®. Specialty compounds have been developed that include FDA grade, chloramine resistant compounds NSF 61 approved , and UL-157 and EN-549 approved for use in propane.

Certifications & Approvals:

Rubber has a variety of physical properties, such as tensile strength, elongation, modulus, compression set, and tear resistance, as well as chemical compatibility. All of these properties must be considered when selecting a rubber to be used in a rolling diaphragm. Contact a DiaCom representative for proper rubber selection.

Chemical Compatibility Tables

Physical Properties

Elastomer Type
(ASTM Designation)

Butyl
(IIR)

Ethylene
Propylene
(EPDM)

Fluoro-
Carbon
(FKM)

Fluoro-
Silicone
(FVMQ)

Hydrin
(CO/ECO)

Neoprene
(CR)

Nitrile
(NBR)

Silicone
(VMQ)

Styrene
Butadyene
(SBR)

Compression Set
Resistance

Good

Fair

Good-Excel

Fair-Good

Fair-Good

Fair-Good

Good

Good-Excel

Good

Durometer Range
(Shore A)

30-100

30-90

50-95

35-80

30-95

40-95

20-90

25-90

40-100

Elongation %

300-800

200-800

100-450

100-500

300-400

650-850

400-600

90-900

400-550

Tensile Strength
(PSI)

2,000+

1,500-3,000

1,500-3,000

350-850

1,500-2,000

2,000-3,000

1,000-3,500

600-1,500

2,000+

Nitrogen Permeability
Resistance

Excellent

Good

Excellent

Poor

Excellent

Fair

Good

Poor

Fair

Resilience

Excellent

Good

Fair

Good

Good

Excellent

Good

Poor-Excel

Good

Mechanical Resistance Properties

Elastomer Type
(ASTM Designation)

Butyl
(IIR)

Ethylene
Propylene
(EPDM)

Fluoro-
Carbon
(FKM)

Fluoro-
Silicone
(FVMQ)

Hydrin
(CO/ECO)

Neoprene
(CR)

Nitrile
(NBR)

Silicone
(VMQ)

Styrene
Butadyene
(SBR)

Abrasion

Good

Good

Good

Fair

Fair-Good

Good

Excellent

Poor-Excel

Excellent

Electrical
Properties-
Insulating

Good

Excellent

Fair

Excellent

Poor-Fair

Fair

Fair

Excellent

Excellent

Electrical
Properties-
Conductive

Fair

Poor

Excellent

Poor

Excellent

Fair

Fair

Poor

Poor

Impact

Good

Good

Poor-Good

Fair

Good

Good

Fair

Poor-Good

Excellent

Tear

Good

Poor

Poor-Good

Fair

Good

Good

Good

Poor-Good

Fair

Temperature Resistance Properties

Elastomer Type
(ASTM Designation)

Butyl
(IIR)

Ethylene
Propylene
(EPDM)

Fluoro-
Carbon
(FKM)

Fluoro-
Silicone
(FVMQ)

Hydrin
(CO/ECO)

Neoprene
(CR)

Nitrile
(NBR)

Silicone
(VMQ)

Styrene
Butadyene
(SBR)

Cold Termperature
Flexibility

Good

Good

Fair-Good

Good

Good

Fair

Good

Excellent

Good

Flame
Retardance

Poor

Poor-Fair

Excellent

Outstanding

Fair

Good

Poor-Fair

Fair-Poor

Poor

Heat Aging

Good

Excellent

Outstanding

Outstanding

Excellent

Good

Good

Excellent

Good

Environmental Resistance Properties

Elastomer Type
(ASTM Designation)

Butyl
(IIR)

Ethylene
Propylene
(EPDM)

Fluoro-
Carbon
(FKM)

Fluoro-
Silicone
(FVMQ)

Hydrin
(CO/ECO)

Neoprene
(CR)

Nitrile
(NBR)

Silicone
(VMQ)

Styrene
Butadyene
(SBR)

Ozone

Good

Excellent

Outstanding

Outstanding

Excellent

Excellent

Poor

Excellent

Poor

Radiation

Fair-Good

Poor

Fair-Good

Good-Excel

Fair

Fair-Good

Fair-Good

Fair-Good

Good

Weather

Excellent

Excellent

Excellent

Outstanding

Good

Excellent

Good

Excellent

Fair

Chemical Resistance Properties

Elastomer Type
(ASTM Designation)

Butyl
(IIR)

Ethylene
Propylene
(EPDM)

Fluoro-
Carbon
(FKM)

Fluoro-
Silicone
(FVMQ)

Hydrin
(CO/ECO)

Neoprene
(CR)

Nitrile
(NBR)

Silicone
(VMQ)

Styrene
Butadyene
(SBR)

Acid-Dilute
Concentration

Fair

Good-Excel

Fair-Good

Good-Excel

Fair-Good

Good-Excel

Fair-Good

Fair-Good

Fair-Good

Aliphatic
Hydrocarbons

Poor

Poor

Excellent

Excellent

Excellent

Good

Excellent

Poor-Fair

Poor

Alkali-Dilute
Concentration

Fair-Good

Good-Excel

Good-Excel

Good-Excel

Fair-Good

Good-Excel

Good-Excel

Good-Excel

Fair-Good

Aromatic
Hydrocarbons

Poor

Poor

Excellent

Good-Excel

Excellent

Fair

Fair-Good

Poor

Poor

ATF Type A

Poor

Poor

Excellent

Excellent

Good

Good

Excellent

Good

Poor

ChlorinatedHydrocarbons

Poor

Poor

Excellent

Good-Excel

Good-Excel

Poor

Fair-Good

Poor

Poor

Diesel Oil

Poor

Poor

Excellent

Good

Excellent

Fair

Good-Excel

Poor

Poor

DiesterLubricants

Poor

Poor

Excellent

Excellent

Good

Poor

Fair-Good

Poor

Poor

EP Lubricants

Poor

Poor

Excellent

Excellent

Poor

Poor-Fair

Fair

Good

Poor

Ethyl Alcohol

Fair

Good-Excel

Excellent

Excellent

Good

Excellent

Good

Excellent

Fair

Ethylene Glycol

Excellent

Excellent

Excellent

Excellent

Excellent

Excellent

Excellent

Excellent

Good

EthyleneGlycol/Water

Fair-Good

Good

Good

Good

Fair

Good

Good

Excellent

Good

Gasoline

Poor

Poor

Excellent

Excellent

Good-Excel

Fair

Good-Excel

Poor

Poor

HydraulicFluids-PetroleumBase

Poor

Poor

Excellent

Excellent

Excellent

Poor-Fair

Fair-Good

Poor

Poor

HydraulicFluids-SilicateEster

Fair

Poor

Excellent

Outstanding

Fair-Good

Good

Good

Poor

Poor-Fair

HydraulicFluids-PhosphateEster

Good

Good

Poor

Poor

Poor

Fair

Good

Poor

Ketones

Good

Fair-Excel

Poor

Poor

Fair

Fair

Poor

Fair-Good

Good

LubricatingOils-HighAniline

Fair

Poor

Excellent

Excellent

Excellent

Good

Good-Excel

Good

Poor

LubricatingOils-LowAniline

Good

Poor

Excellent

Excellent

Excellent

Fair

Fair-Excel

Poor-Fair

Poor

Silicone Oil

Good

Excellent

Excellent

Excellent

Excellent

Excellent

Good

Poor

Good

Steam-Above
250°F (121°C)

Poor-Fair

Excellent

Fair

Poor-Fair

Poor

Fair

Fair

Poor-Fair

Poor-Fair

Water-212°F(100°C)

Good

Excellent

Excellent

Excellent

Good

Good

Excellent

Excellent

Excellent

For Product Inquiries & Information Only:

The information contained herein is believed to be reliable, but no representations, guarantees or warranties of any kind are made as to its accuracy, suitability for particular applications or the results to be obtained therefrom. Nothing contained herein is to be considered as permission, recommendation nor as an inducement to practice any patented invention without permission of the patent owner.